Whoosh, big progress today. Worked out the battery holder upgrade and the water pump and tried to find the correct amount of bits for some events. Some information on the events and their parameters:


Water
Water blocks are made with the Water event. You will have to give it an ID and of course you must specify its dimensions. The first boolean, Filled, decides if the water block is 'filled' at the start of the level, so that there is water in there. The second boolean, Mode, allows you to switch bedween two modes: the first one (0) has a diagonal end at the top right corner, the second one (1) has an all-straight vertical right end.
The Water event needs the Water Options event somewhere in the level to work. In the Options event, the color of the water (maybe among other settings) is decided. I still have to figure out its parameters, maybe I'll try to do so tomorrow.
You can fill an empty water block and you can flush a full water block with a Water pump. For this event to work, you must specify a Global ID and the IDs of the water blocks that must be changed. In this case, the Global ID refers to the Global ID number of a Battery holder. When you put a battery in it, the pump is activated and will fill the water block with the ID you entered for the 'Empty water ID' parameter and will flush the water block with the ID you entered for the 'Full water ID'. This will look like one water block is being filled with water from another.
Liferafts can be placed on water by putting them on the place you want them to float on the water and setting their Water ID number to the same value as the water block you want them to float on. It turned out it doesn't matter if the Liferaft event is placed in the level under the water surface, it will automatically be moved to the water surface.

Battery holders
Battery holders have an ID number. When you put a new battery into the battery holder, all objects on the level that have the same Global ID will be activated. If there is a Battery holder update event in the level with the same Global ID, the Battery holder with that ID will have a small device connected to it which enables the battery holder to take infinite energy from the battery you put in.

Eyecandy events
It turned out that there are events in the game that only add some eye candy. The monitor event will show a monitor with some person displayed on it. The Leaking energy event will show a small fireworks-like animation now and then. The effect is similar to what you get if you cut a wire while its plug is in the wall (use scissors with plastic on them please, don't die). The Dripping Water doesn't seem to harm you.